Metal spray gun



Jn-447', 1941. H. s'. INGHAM. 2,227,752'v HETAL'SPRAY GUN Filed June so,195e `s sheets-Sheet 2 Nm QS; v

N E l .y Ln m- .l

` AWORNEY.

Jan. 7, 1941. H.: s. ING'HM METAL SPRAY GUN Filed Juli@ so. 193s ssnets-sheet s "INVENTOR, l

H. S. INGHAM METAL SPRAY GUN Filed June 30. 1938v 46 Sheets-Sheet 4INVENTOR. Mur/t n l i v BY l (i 1 i ATTORNEY.

Jan. 7,1941.

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'- H s'. INGHAM A' '2.227352 METAL SPRAY GUN Filed Julie :so '193s '6skeins-sheet 5 ign;

4Patented Jan. 7, 1941 UNITED] 'STATES PATENT OFFICE 2,227,752 METALseau GUN t Herbert s. Ingham, Jamai-ea, N. Y. Application June 30,1938,semina. 216,654

14 claims. (Scl. 91-122) My invention relates to metal spray guns andwill be fully understood from the following description read inconjunction with' the drawing Ain which: l 5 Fig. 1 is a side view of a.metal spray gun constructed in accordancel with my invention.

Fig. 2 is a vertical section through the construction shown in Fig; 1 onthe plane indicated by III-II.

A1 0 Fig. 3 is a verticalsection through the con- 1 struction shown inFig. 2 on the plane indicated bym-III. Y Fig. '4 is a vertical sectionthrough the cony struction shown in' Fig. 1 on the plane indicated l5.by 15V-IV.

Fig. 5 is a vertical section through the construction shown in Fig. .lon the plane indicated by, V.V. Y d v Fig. 6 is an exploded sectionthrough the construction shown in Fig. 1 on the plane indicated' byv1-vr.

Fig.'6aiis a. plan view of the interior of the construction shown 'inexploded form in Fig. 6.

Fig. '1 is a side view of one element of the gun constructed inaccordance with my invention;

Fig. 8 is a view of the construction shown in.

Y Fig. 'Z at a right angle to the showing in Fig. 7.

Fig. 9 is a central Vvertical section parallel to the construction shownin Fig. 1. y

Fig. 10 is a vertical section through the'construction shown in Fig. 5on the plane-indicated by'X--X Y Fig. 11 is a'section on theplaneindicated by XI-XI in Fig. 5. Fig. 12 is an exploded sectionthrough the construction shown-in Fig. 11 on the plane indicated byXII-XLI.

Fig. 12ais a perspective view of the plug oi the nozzle shown in Fig.12. v

40 I Fig. 131s a fragmentaryview of the face of the Fig. 15 i's asection on the plane indicated by XI-xr m Fig. s showing al1-alternativeembodiment' of my invention.

"50 Fig'. 16 is a corresponding section showing a further alternativeembodiment of my invention.

I Fig. 17 is acorresponding section showing a further alternativeembodiment of my invention. Fig. 1,8 is a corresponding' sectionshowing'a 55 still further embodiment oi my invention.

Metal spray guns of the type to`which my invention relates are deviceswhich operate by con tinuously feeding a metal rod orwire into a zone inwhich it is melted and from which this melted metal is sub-divided andpropelled by a blast of 5 air or other gas. The rod or wire is fed intothe melting zone by knurled burs which press against opposite sides ofthe wire and are driven by a gas Y turbine operating through reductiongears. The load on the turbine varies from time to time due 10 tochanges in the position of the operator, kinks Ain the wire, etc., andsince it is essential that the rate of feed of the wire beuniformlymaing tained, it is likewise essential that the turbine haveacomparatively stable speed of operation, 15

Ai. e., that its speedbe affected as'little as possible by variations inthe load. This may be accomplished by` appropriate turbine construction.

In the ope'ration of metal spray guns, it is, however, necessary tomaintain different rates of feed 20 when spraying different metals;for,V example, 'metals, the heats of fusion of which are low, may

be fed and sprayed more rapidly than metals with a high heat of fusion,and wires of larger diameter are fed and sprayed more slowly than .wires25 of the same material of smaller diameter.4 In usual practiceaneii'ort is made to approximate proper conditions for the particularmetal being sprayed by the provision of replaceable gearing designed topermit the gun to be operated at the 30 desired rate of'vwire feedWhilefpermitting the turbine 4to operate within a range of stable op- Aeration. Changing the gearinginvolves a loss of time and the possibilitythat metal' particles will be picked up by the gears in handling andinter- 35 fere with the operation' of the gun. If an eiort is made toreduce the turbine speed by throttli'ng Y the gas the turbine becomesunstable and a uniform wire `feed isno longer maintained.

I have devised anew metal spray gun in which 40 no change of gearing isnecessary and by means of which it 'is nevertheless feasible to maintaintwo or, in fact, any number of rates of wirerfeed within practicallydesirable, shifting from one speed to another by simple adjustment andnotwithstanding such changes in the `rates of feed, maintaining theturbine at all times in a range of stable operation.

Broadly speaking, I accomplish this purpose by varying the total throatarea of the turbine nozle or nozzles and this may be done within .thescope of myinvention, either by means for continuously varying thethroat area over a predeterstable. This reduction in manifold pressuremay` be the result of a restriction intermediate the air supply and thejets, but in the preferred construction the rate at which the manifoldpressure v decreases as the nozzle area is increased is determined bycontrol means incorporated in the gun which may, for example, take theform either of a ilxed oriilce or va variable valve between the manifoldand the air line. In the preferred practice this is controlled by theneedle valve which governs the air flowing into the manifold. Theoperator selects that adjustment of the area of the nozzle or nozzles inuse which will maintain the turbine in stable operation at approximatelythe desired speed, and then adjusts the needle valve to give the preciserate of wire feed required.

In accordance with the principle of my invention, where I provide aturbine nozzle or nozzles, the throat area of which may be continuouslyvaried, any number of stable operating speeds may be obtained bycorresponding adjustment of the total throat area in service.Alternatively, I may, in accordance with the principle of my invention,use a number of jets .each of fixed throat area, and place in service ajet or combination of jets of progressively greater throat area.

For the purpose of illustrating the scope and character of my invention,I have hereinafter described a spray gun containing certain practicalembodiments of the same. Referring to the drawings, I (Fig. 2) indicatesthe inlet for oxygen w or other combustion supporting gas 2 the inu letfor acetylene or other combustible gas, and

3 the inlet for air or other gas for use to project the metal spray anddrive the turbine.

Each of the said inlets is connected by a suitable tting and ilexibletubing to a source of required gas. When plug 4 of valve 5' is in theposition shown, each of the inlets registers with a corresponding holein the plug, these holes being indicated by numerals 5, 5 and Irespectively. When handle 8 and plug 4 are in the position shown, oxygenflows through duct I0 into duct The combustible gas flows through ductI2 to mix with the oxygen in duct II. The airv ows through duct l5 intochamber` I6 and also flows through the side connection Il controlled byneedle valve I8 into turbine manifold `I9. Openings 5, 6, and I in plug4 are so arranged that as handle 8 is turned from the ol position whichis at a right angle to the showing in Fig. 2 iirst some combustible gaspasses into duct and thence to the burner'outlet to enable the burner tobe lighted, some air passes simultaneously into manifold I9 to'enablethe turbine to come up to speed. Alternatively all the valve passagesmay be opened but at such rates of llow as to establish favorablelighting conditions which are different from the conditions obtainingwhen the gun is in operation. This position of the valve ls called thelighting position. Under former practice a certain degree-of experiencewas necessary to enablethe operator to turn the handle 8 to the exactposition at which the burner may be properly lighted, but with myconstruction this difllculty ls` eliminated, the washer 2|)A (Fig. 3)defines a hole 2| slight pressure against handle 8 forces the depression23 out of engagement with the head of the pin 24. A further movement ofhandle 8 causes oxygen to flow through duct I@ which establishes amelting flame with the ignited gas and the final movement of handle 8 tothe position shown in Fig. 2 permits air to flow into duct 'I5 andthence into chamber I6 to project the sprayed metal upon the surface tobe covered.

The construction of that part of the gun by which the rod or wire ismelted and projected will be explained by reference to Fig. 9. The wirey3'!! moves forward to guide 3I and through duct 32 to the interior 33of the burner tip 34. The mixture of air and oxygen move forward throughthe duct which is immediately behind duct 32 (the arrangement is shownin Fig. 2) and into the annular space 35. From this annular space 35 thecombustible mixture moves forward through a number of holes to bedischarged through convergent oriilces 36 against the wire. 'I'his formsa zone of gases undergoing combustion, whereby the wire 3l melts asrapidly as it is progressively advanced into the zone, for which reasonthis zone may be hereinafter referred to as a melting zone. The air fromchamber I5 advances through the annular space 40 surrounding burner tip34 and is projected by air nozzle 4| in such a way as to sub-divide andpropel the molten metal. The air tip 4| is threaded to the outer shell42 of the burner so that the orice 43 dened by conical interior of airtip 4| and conical exterior of burner tip 34 maybe adjusted withcorresponding variations in the characteristics of the air blast. kWhena satisfactory adjustment has been made. the tip 4| is locked inposition by the lock nut 44. It will be noted that the air in passingforward from the chamber I6 goes through the constricted annular space45 which exerts a deflnite control over the volume of air passing. As aresult of this constriction and the orifice effect thereby created, theadjustment of air tlp 4I modifies the characteristics of the air blastwithout so great a modification of the volume of air passing thereto aswould otherwise result, which is decidedly advantageous in theadjustment and operation of the gun.

The wire 31 (Fig. 9) enters the. gun through the annular guide 50 ofhardened material in which is the duct 5|. The upper and lower surfacesof the wire are engaged respectively by the burs 52 and 53. Bur 53 iscarried by shaft 54, which shaft is driven by an air turbine throughsuitable intermediate gearing which will be here` inafter described.Shaft 54 (Fig. 4) also drives the gear 55 in mesh with gear 56, which inturn drives the upper bur 52. Both gear 56 and bur 52 are secured to thetubular member 51 which rotates on the spool 58 carried by pin 53 (Fig.4). The screw 59 is carried by the saddle 30 and this saddle ispivotally secured (Fig. 9) to frame 6| of the gun by the hinge 62. Whencap 65 is turned the threaded end 66 of the screw 6l advances into thethreaded member 63 which is a part of frame 6| and the spring 'l0exerts'pressure on the saddle 50, thereby forcing the upper bur 52toward the 75 lower bur 53 and thereby causing the burs to engage andadvance the wire 3l. Conversely, when cap B5 is turned in the `reversedirection, pressure of spring Iv on saddle` 50 is released and the bursmove freely without engaging and advancing the wire.

The shaft 54 (Fig. 4) which drives bur 53 is mounted in ball-bearings'I0 and 1|. Bearing 10 is held in frame 6| and bearing Il is held in thehousing I2 which is attached to frame 6I. .The shaft 501s driven by theworm gear 13, which in turn is driven by the worm 14, carried by theshaft 15. Shaft 'I5 (Fig. 10) is carried by ballbearings 'i5 and 'limounted in the housing` 12. Shaft 151s in turn driven through the wormgear yby the worm 19. The worm 419 (Fig. 5) is integral with shaft 80carried by bearings 85 and 86. Bearing 85 is mounted in housing 12 andbearing 36 is mounted in the cap or cover 90 of the turbine 9|.

Turbine 9| (Fig. 5) includes the turbine rotor drum 05 secured to shaft80 by the set screw 36. Details of the binding |00 are apparent fromFigs. 7 and 8. As evident from the exploded view (Fig. '6) of the cover30. this cover includes the mounting |0| for the ball-bearing 36 andthree ridges |02 radially arranged about mounting |0|on the interiosurface of the cover. The washer-shaped member |03 is made of fine wiremesh and rests directly upon ridges |02. The washer |04 rests directlyon the-washer '|03 and is composed of liber. The fiber washer |00defines the perforations |05 (Fig. 6a). 'I'he washers |03 and |00 areheld in contact with each other and with the ridges |02 bythe strips|08, which in turn are secured to the ridges- |02 by the screws |01.'One result of this construction is that the exhaust from the turbineflows through perforations |05 in the ber washer E00, thence through theopenings in the fine screen of which washer |03 is n composed, andthence through exhaust ports of the-turbine H0, formed in the cover 80(Fig. 6 and Fig. 1) thereby resulting in more quiet operation of theturbine; The strips |00 form ridges in the space in which the bladeddrum of the turbine revolves. These ridges operate to broaden the rangeoi stable operation iol' any given setting of the turbine nozzles byproducing turbulent now of gas within the turbine.

One nozzle arrangement falling within the purview of my invention isshown in Figs. 11, i2, im, i3, and le. Fig'. ll shows the face H5 which(together with thehousing 90) denes the space in which the turbine drumrotates; the mi is not shown to facilitate inspection of the nozzlestructure. In this ca se one individual nozzle lib is shown which isofvariable area.

l'This nozzle is composed of the bore Ill and the plug il@ which isturned within bore ||1 to vary the eective area of the nozzle. Theactual form oi the delivery opening' i lgifrom which the gas isdischarged is shown in Fig. 13, which is a view ofthe face lib? at thepoint at which the nozzle discharges. It is evidentfromthis thatapproximately half di the bore Ill is available for discharge. Fig. leis a section through Fig. l2 on the plane indicated by mV-XW (with theplug in operative position). `By inspection or this heure, it `isevident that gas in the space l@ between the plug H0 and thelongitudinally extending barrier B2i cannot esy trary, the only openingthrough which air may escape is that part oi' the opening il@ which sonthe actual nozzle in use at any one time may be enlarged or decreasedwithin the limitsshown in Fig. 13 by turning the plug H8.

The preferred formof nozzle for practical applications is that shown inFig. 15 in which the nozzle is permanently connected to the manifold I9while nozzle |3I may at any time desired be additionally connected byturning plug |32 so that hole |33 defined by the plug regis- Y ters withinlet |34 of nozzle |3|. In this case it is evident that when both jetsare in operation, the effective nozzle area is greater than with either`jet individually, and in this case two stable ranges of operation maybe obtained by using either-Jet |30 alone or by the combined use of jets|30 and |3I. As hereinbefore pointed out, a slower stable range ofoperating speeds is obtained by increasing the effective nozzle area.

A further alternative form of construction is that shown :in Fig. 16inwhich case I have shown two nozzles, |35 and |33, which may be`alternatively brought lnto communication with ,theA

fective discharge areas and that the lower stablerange of operatingspeeds is obtained by the use of the jet of greater'discharge area. Thetubular section |38 may in addition carry another set of holessimultaneously registering with the inlets to nozzles |35 and |33 sothat both nozzles may be simultaneouslyV in use whereupon a third andstill lower stable range of operating speeds-will be obtained. A furtheralternative embodiment of my invention is shown in Fig. 17. This alsocomprises two nozzles which maybe alternatively used. Nozzle |00 'is incommunication with manifold I9 through side-arm |4| and is controlled byneedle valve |42.` Nozzle |43 is in vcommunication with manifold I0through side-arm |44 and is controlled by needle valve |05. In case thenozzles shown are of the same or substantially the same cross-sectionalarea. a lower stable range of operating speed of the turbine is obtainedby placing both nozzles simultaneously in communication with themanifold. The nozzles may, however, be constructed with dierentcross-sectional areas, in which case a lower stable operating speed isobtained by the use of the nozzle oi greater cross-sectional area and astill lower stable range of operating speeds is obtained by thesimultaneous use of both nozzles. Since Iin this case the amount of gasdischarged from each Jet maybe accuratelydetermined by the needle valvecontrolling it,`the use of a restriction or valve controlling theadmission of air into the manifold I0 is not essential although inpractical operation it is desirable.

A still further embodiment of my invention ls shown in Fig. 18 in whichcase the turbine is provided with four separate nozzles, numbered.

respectively |50, |51, |52 and [158. Communication of these nozzles withmanifold is is controlled by tubular section ld of the plug it inmanifold I. The sleeve is provided with slots so that nozzle |53 may beplaced in service alone or nozzle |52 may be additionally placed inservice or nozzle i5! may be placed in service in addition to nozzle |52and E53 or ifdesired, all four nozzles may be placed in service. In thislili way any one of four stable ranges of operating speed may beobtained, the speed being inversely related to the number of nozzles inoperation and to the total cross-sectional area of the nozzles inoperation. It will, of course, be understood that in this embodiment ofmy invention, the nozzles may be constructed with cross-sectional areadifferent from one another so that a corresponding control would beobtained by their alternative use and if desired additional ports may beprovided in th'e tubular section |54 so that these nozzles may also becombined with one another in various ways to produce additional rangesof operating speed.

The foregoing description is furnished by way of illustration and not oflimitation and it is, therefore, iny intention that the invention belimited only by the appended claims or their equivalents wherein I haveattempted to claim broadly all inherent novelty.

Iclaim: v

' 1.In a metal spray gun of the molten metal gas blast 'type having `aninlet for .compressed gas and turbine actuated means for progressivelyadvancing metal into a melting zone andincluding Y in said turbine arotor drum and nozzle means positioned to direct a blast of gas againstthe blading of said ro'tordrum, the improvement lcomprising a manifoldin communication with said nozzle means, means for varying the area ofthe nozzle means in use and pressure reduction means between said inletand said manifold.A

2. The improvement in a metal spr-ay gun a'ccording to claim 1 in whichsaid turbine comprises in addition at least one gasbaie within theA samepositioned to produce turbulent flow of gas 'therein in air frictionalengagement with said rotor drum.

3. In a metal spray gun of the molten metal gas blast .type havinganinl-et for compressed gas' and turbine actuated means for progressivelyadvancing metal into a mel-ting zone and including in said turbine arotor drum and a nozzle positioned yto direct a blast of gas against theblading of said rotor drum, the improvement comprising `a manifold incommunication with said nozzle, mean-s for varying the cross-sectionalarea of said nozzle and pressure reductionmeans between said inlet andsaid manifold.

4. The improvement in a metal spray gun according to claim 3 in whichsaid turbine comprises in addition at 'least one gas baille within thesame positioned lto produce turbulent ow of gas therein in airfrictional engagement with said vrotor drum.

5. In a metalspray gun of the molten met-al gas blast type having aninlet for compressed gas and turbine actuated means for progressivelyadvancing metal into a melting zone'and including in said turbine arotor drum and avplurallty of nozzles positioned to direct a blast of'gas aagainst the Ibllading of said rotor drum, the improvementcomprising a manifold in' communication with said nozzles, means forvarying the average area of the nozzles in use and. pressure reductionmeans between said inlet andsaid manifold.

6. In a metal'spray Igun of the molten metal gas blast type having aninlet for` compressed gas Ipositioned to direct a bia-st of gas againstthe blading of said rotor drum, the improvement 'comprising a manifoldin communication with said nozzles, means for varying the number ofnozzles in use' and pressure reduction means between said inlet and saidmanifold. '7. The improvement in a metal spray gun according to claim 6in which said turbine comprises in addition at least one gas baillewithin the same positioned to produce turbulent now of gas therein inair frictional engagement with said rotor drum.

8.,.In metal spray gun of the molten metal gas blast type having aniniet for compressed gas and turbine actuated means for progressivelyadvancing metal into a, melting zone and including in said turbine arotor drum and a number of nozzles of different cross-sectional areaspositioned to direct a. blast of gas against the blading of said rotordrum, the improvement comprising a manifold in communication with saidnozzles, means for selectively placing a part of said noz- V zle's inuse, and pressure reduction means between said in'let and said manifold.

9. The improvement in a metal spray gun according to claim 8 in whichsaid .turbine comprises in addition at least one gas baille within thesame positioned |to produce4 turbulent flow of sas therein in airfrictional engagement with said rotor drum.

10. In Ia metal-spray gun of the molten metal gas blast :type having aninlet for compressed gas and turbine actuated means for progressivelyadvancing metal in'to a melting zone and including 30 in said turbine arotor drum and nozzle means positioned to direct a bilastof gas againstthe blading of said rotor drum, the improvement compri-sing meansincluding at least one gas baille i-n said. turbine positioned t0produce Iturbulent flow of 'gas therein in air friotional engagementwithk said rotor drum.

l1. `In a metal spray gun of the molten metal gas blast type having aninlet for compressed gas and turbine actuated means for progressivelyadvancing metal into a. melting zone and including vin said turbine arotor drum and nozzle means positioned to direct a blast of gas againstthe blading of said rotor drum, the improvement comprising meansincluding at least one station stationary internal projection positionedto produce turbulent now of gas therein in air fric'- tional engagementwith said rotor drum.

12. In a metal spray gun of the type including means for maintaining a.Ymelting zone, means for directing a blast of gas againstmetal which hasbeen melted in said zone adapted to subdivide and convey such meltedmetal, a control cock for gases required inv the operation of said gun,said control cock including a housing defining multiple inlets andcorresponding outlets, and "including a handle operated plug defining4atleast three passages, each of said passages controlling ilow throughone of saidA inlets and the corresponding outlets, at least one of saidpassages dening a port for combustible gas, at least one other a portfor oxygen and atleast one-third a port for a compressed non-combustiblegas, the

improvement; comprising gas bleedingmeans in advancebfl the registry ofsaid port for combustible gas with its inlet and outlet in substantiallylighting` position, and a. detent positioned vto arrest the motion ofsaidplug when said bleeding means are in said lighting position.

13. In a metal spray gun of the type including means formaintaining amelting zone, means for directing a blast of gas against metal which hasbeen melted in said zone adapted to sub-divide `ing a handle operatedplug dening at least three passages, each of said passages controllingflow through one of said inlets and the corresponding outlet, at leastone of said passages deilnlng a port for combustible gas, at least oneother a port for oxygen and at least one-third a port for a compressednon-combustible gas, the improvee ment comprising first gas bleedingmeanswithin said housing positioned to bring into communicationl saidcombustible gas inlet and outlet in advance of the registryof said portforv combustible gas with its inlet and outlet in substantially lightingposition, second gas bleeding means within said housing positioned tobring into communication said compressed non-combtible gas inlet andoutlet in advance of the registry of said port for compressednon-combustible gas with its inlet and outlet-in substantially lightingposition and a detent positioned to arrest the motion of said plug whensaid first and said second bleeding means are in said lighting position.

14. In a metal spray gun of the type including means for maintaining amelting zone, means for directing a blast of gas against metal which hasbeen melted in said zone adapted to sub-divide and convey such meltedmetal. a control cock for gases required in the operation oi said gun.said control cock including a housing deiining multiple inlets andcorresponding outlets, and including a handle operated plug dening atleast three passages, each of said passages controlling ow` through oneof said inlets and the corresponding outlet, at least one of saidpassages defining a -port for combustible gas, at least one other a portfor oxygen and atleast one-third a port for 'a compressednon-combustible gas, the improvement comprising rst gas bleeding meanswithin said housing positioned to bring into communication saidcombustible gas inlet and outlet in advance of the registry of said portfor combustible gas with its inlet and outlet in substantially lightingposition, second gas bleeding means within said housing positioned tobring into communication said compressed non-combustible gas inlet andoutlet in advanceof the registry of said port for compressednon-combustible gas with its inlet and outlet in substantially lightingposition, third bleeding means within said housing positioned to bringinto communication said oxygen gas inlet and outlet in advance of theregistry of said port for oxygen with its inlet and outlet insubstantially lighting position and a detent positioned to arrest themotion of said plug when all of said bleeding means are in said lightingposition.

HERBERT S. NGHAM.

